(a) Technical Field
The present disclosure relates to a transflective liquid crystal display, and more particularly, to a transflective liquid crystal display including a transistor array panel and a manufacturing method thereof.
(b) Discussion of the Related Art
A liquid crystal display (LCD) includes a panel assembly including, for example, a transistor array panel, a color filter panel, and a liquid crystal layer interposed therebetween. Since the LCD is a non-emissive device, a backlight unit for supplying light is provided behind the panel assembly. The transmittance of light emitted from the backlight unit is determined according to an alignment state of liquid crystal molecules in the liquid crystal layer.
Types of LCDs include a transmissive LCD for displaying an image by using an internal light source such as, for example, a backlight unit, a reflective LCD for displaying an image by using external light such as, for example, natural light, and a transflective LCD. The transflective LCD includes a transmissive display mode and a reflective display mode. The transmissive display mode, where an image is displayed by using an internal light source, can be used where external light is limited such as, for example, indoors or in a dark place. The reflective display mode, where an image is displayed by reflecting external light, can be used where the external light is sufficiently provided such as, for example, outdoors or in a bright place.
The transmissive LCD includes a backlight unit provided behind the panel assembly, and light emitted from the backlight unit passes through the panel assembly. The transmissive LCD consumes more power and is heavier and thicker compared to the reflective LCD.
The reflective LCD consumes less power compared to the transmissive LCD because the backlight unit is not used. However, the reflective LCD using external light may not display an image properly when external light is not sufficiently provided.
The transflective LCD can have sufficient luminance irrespective of ambient brightness because internal and/or external light can be used.
A conventional transistor array panel of the transflective LCD is usually manufactured by using about seven or eight masks. Masks are used for, for example, forming a gate electrode, a semiconductor layer, a source/drain electrode, a contact hole on a protective film, a contact hole in an organic insulating layer, a transparent electrode, and a reflective electrode.
The transflective LCD may employ a dual cell gap structure between a reflective region and a transmissive region of a pixel portion to reduce non-uniform luminance caused by, for example, a path difference of light. However, due to a step difference of an organic film for forming the dual cell gap structure, a transparent electrode and a reflective electrode can be disconnected in the transmissive region. Further, an etching process for forming the reflective electrode can damage the transparent electrode. In addition, when the transparent electrode is formed at a step difference, an etchant for the reflective electrode can flow along the step difference to the transparent electrode. In such a case, the transparent electrode may be eroded.